Regenerative type periodic flow devices are conventionally employed to expose fluid streams to constituents or to transfer heat or constituents from one fluid stream to another, and thereby from one area or zone in space to another. Such device might be used to achieve one of heat transfer, mass transfer, catalysis, ion exchange, separation of the fluid media, removal of organic compounds from the fluid media, dilution or concentration of fluid components, treatment of fluid-carrying organisms, and the capture and retention of hazardous materials. Typically, these devices are in the form of a "wheel". The direct contact of the stream to the constituents or the transfer of heat or constituents from one fluid stream to another is then accomplished as the wheel rotates.
The one common type of wheel is around a cylindrical hub and applying commonly constructed by wrapping a corrugated material around a cylindrical hub and applying a rim around the wrapped core. The wrapped core is further held in place by extending spokes radially through the core between the hub and the rim.
Wheels of such construction are used in cycle air-conditioners, which are known in the art and are based primarily on the Munters Environmental Control system (MEC) unit as described in U.S. Pat. No. 2,926,502. As set forth in this patent, the basic open-cycle air-conditioner operates by dehumidification and subsequent cooling of air wherein moist hot air is conditioned by basically a multi-stage process to produce cool air.
In open-cycle air-conditioning systems, a basic multistep approach is used. This is shown, for example, in Coellner et al. U.S. Pat. No. 4,594,860. In the inlet path, outside air is subjected to removal of moisture through a moisture transfer wheel, with the dried air being cooled by means of a heat exchanger wheel with the subsequent addition of moisture by an evaporative element so as to further cool the air before it enters the area to be conditioned. In the return cycle, the air passes through an exhaust path which includes a further evaporative element, the heat exchanger wheel, a heating element, and the moisture transfer wheel, after which the air is exhausted to the atmosphere. In the return cycle, also called the outlet path, air passing through the moisture transfer wheel accomplishes the regeneration of the wheel by driving moisture therefrom.
The mechanical subsystems which envelop the core section of each wheel are extremely critical to the operation and longevity of the assembly, particularly the core. The factors important to the core include: (1) the mechanical system used to effectively seal one fluid stream from another, (2) alignment of the core with respect to the mechanical sealing system, (3) the means used to maintain the structural integrity of the wheel including the core, (4) the means used to support and rotate the wheel, and (5) the means by which the various subsystems are combined to house the core in a modular assembly, typically referred to as a "cassette".